Well according to Herminia Ibarra and her colleagues, writing in the September 2013 HBR, persistent gender bias disrupts the learning process of becoming a leader.

They are talking about what they call “second generation gender bias“. Not direct discrimination but things like the paucity of role models for women, career paths and jobs that have become entrenched with a gender bias, and women’s lack of access to sponsors and networks.

They also talk about the double binds facing women. In most cultures leadership is associated with masculinity.The ideal leader, like the ideal man, is decisive, assertive, and independent.Women, on the other hand, are expected to be nice, caretaking, and unselfish.

Research shows that female leaders who excel in traditional male domains are viewed as competent but less likeable than their male counterparts. Yet research shows that female CEOs are trusted more than male ones and can add real value to teams.

Behaviours that suggest self-confidence or assertiveness in men often appear arrogant or abrasive in women. Female leaders who adopt a feminine approach to their work may be liked but not respected. They are seen as too emotional to make tough decisions and too soft to be strong leaders.

Yet research carried out by Zenger and Folkman in 2011 on over 7,000 executives using 360 degree feedback, showed that women were rated higher than men at every managerial level. However the higher in the hierarchy you went the more men there were. So were companies promoting the right people?

They used 16 competencies in their research, which they had identified as being the most important in terms of overall leadership effectiveness.

These were:

Takes initiative

Practices self-development

Drives for results

Develops others

Inspires and motivates others

Builds relationships

Collaboration

Teamwork

Establishes stretch goals

Champions change

Solves problems and analyses issues

Communicates powerfully and prolifically

Connects the group to the outside world

Innovates

Technical or professional expertise

Develops strategic perspective

Comparing mean scores for men and women the women scored significantly (statistically) higher than the men on 12 of the 16 traits – and not just the ones that women are known to be better at. They scored the same as men on connecting to the outside world, innovating, and technical or professional expertise.

The only trait where men scored higher was on developing a strategic perspective.

So what’s to be done? Ibarra and her colleagues don’t suggest anything dramatically new or innovative.

Progressing to leadership positions means leaving behind your old professional identity and learning new skills (have a look at Charan’s pipeline model).

That can be scary so having supportive mechanisms in place such as providing leadership programmes, mentoring and coaching (and I find in my coaching that women are less defensive and often respond better than men), and providing a support group or a safe space – perhaps an action learning group – can make a real difference.